Macrauchenia patachonica Owen (Mammalia, Litopterna) de la région de São Raimundo Nonato (Piauí, Nordeste brésilien) et la diversité des Macraucheniidae pléistocènes

The São Raimundo Nonato (Piauí, Northeastern Brazil) area yielded about 50 Macraucheniidae remains. The study of this material and of other fossils from Northeastern Brazil (Paraíba, Pernambuco, Rio Grande do Norte) shows a great similarity to Macrauchenia patachonica as it was defined in Argentina, which is the most abundant of the three species pertaining to the genus. Thus the taxon Xenorhinotherium bahiense created in 1988 by Cartelle et Lessa for a material discovered in the Bahia State and assigned to use for all the Quaternary Litopterns from tropical Brazil appears to be no more than a junior synonym of it. M. patachonica seems to have occupied very varied biotopes from sea level up to a high of 4000 m, and from the cold Southern Patagonia to the Equatorial Venezuela. The species lived from the Middle Pleistocene up to the beginning of the Holocene.     

Ectoine as the predominant osmolyte in the marine bacterium Marinobacter hydrocarbonoclasticus grown on eicosane at high salinities

L. FERNANDEZ-LINARES, R. FAURE, J.-C. BERTRAND AND M. GAUTHIER. 1996. Ectoine was detected by ¹³C-nuclear magnetic resonance spectroscopy in extracts of the halophilic marine bacterium Marinobacter hydrocarbonoclasticus grown at different NaCl concentrations (0.6, 1.5, 2.5 mol l^-1) in synthetic seawater on eicosane as the sole source of carbon and energy. Ectoine was synthesized as the principal osmolyte in response to stress. However, when the medium was supplemented with glycine betaine, this osmolyte was transported into the cells and replaced ectoine.     

Simultaneous radioimmunoassay of 5α-amdrostane-3α, 17β-diol and 5α-androstane-3β, 17β-diol unconjugated and conjugated in human serum

The simultaneous determinations of both 3α and 3β epimers of 5α-androstane-3, l7β-diol as their glucuronides, sulfates and in their unconjugated forms are described. The diol estimation is carried out by radioimmunoassay with two specific immune sera after purification of the serum by use of chromatography on Sephadex LH-20. The values obtained (mean ± S.D.) in pg/ml for the unconjugated 3α and 3β epimers were, respectively, 267 ± 67 and 816 ± 76 for men; 114 ± 33 and 515 ± 177 for women; 142 ± 77 and 779 ± 200 for hirsute women. Among the conjugates, the most important were the sulfoconjugates, their rates being, respectively, (men ± S.D. in ng/ml) 41.3 ± 9.5 and 103 ± 40 for men; 12.4 ± 3.1 and 51.2 ± 14.9 for women and 36 ± 22 and 72 ± 36 for hirsute women. Differences in the conjugation of both epimers were also noticed.     

Ethanol-resistant mutants of Nicotiana plumbaginifolia are deficient in the expression of pollen and seed alcohol dehydrogenase activity

Summary Six independent mutant lines ofNicotiana plumbaginifolia resistant to ethanol, designated E3, E8, E101, E112, E144 and E251, were isolated as germinating seedlings on selective medium. In all cases, resistance to ethanol was conferred by a single recessive nuclear mutation at the same locus. Mutant seeds and pollen lacked detectable ADH activity, with the exception of E251 where a residual activity was detected. An antiserum directed againstArabidopsis thaliana ADH detected an ADH-related polypeptide of 44 kDa present in wild-type seeds and, to a lesser extent, in the seeds of the leaky mutant E251. No ADH-related polypeptide could be detected in seeds of the other mutants. However, all of them had a nearly normal level of ADH mRNA except one which did not synthesize any mRNA. These results suggest that these ethanol-resistant mutants are impaired in one of the structural genes coding for alcohol dehydrogenase. The corresponding locus has been designatedAdh1.Abbreviations ADH alcohol dehydrogenase - EMS ethyl methane-sulfonate - MTT dimethyl thiazol tetrazolium - NAD nicotinamide adenine dinucleotide - NBT nitro blue tetrazolium - p-cells protoplast-derived cells - PMS phenazine methosulfate - SDS sodium dodecyl sulfate     

Hydroxocobalamin treatment of hypercyanemia and hypercyanuria following sciatic nerve compression in rabbits]

Compression of sciatic nerve of rabbits with an inoxidizable clip increases free and combinated cyanides levels both in blood and urine in days following the operation. A treatment with hydroxocobalamin decreases them significantly.